Synthesis and characterization of β-lactam functionalized superparamagnetic Fe3O4@SiO2 nanoparticles as an approach for improvement of antibacterial activity of β-lactams

Abstract

In this paper, we reported, for the first time, a new multistep method for preparing β-lactam functionalized Fe₃O₄@SiO₂ nanoparticles with high saturation magnetization. The synthesized nanostructures were characterized by FT-IR, XRD, TEM, FE-SEM, TGA, DLS, N₂ adsorption–desorption isotherm analysis, elemental analysis, NMR and mass spectroscopy. Also, the magnetic properties of these Fe₃O₄ nanoparticles allowed the simple separation of these nanoparticles from the reaction mixture by an external magnetic field. β-Lactams (2a–f) and nano Fe₃O₄@SiO₂/β-lactams (3a–f) were tested against Gram-positive S. aureus (ATCC 25923) and Gram-negative Escherichia coli (ATCC 25922) and results showed the minimum inhibitory concentrations (MICs) of 3a–f were less than 2a–f.